Pumps are a critical asset in agriculture. As water becomes scarcer due to climate change, farmers have to dig deeper to have access to ground-water and to compensate for lack of rain or State water through a network of canals. The depth of a well has increased from a few hundred feet to a few thousand feet. The cost per feet increases as well as traditional well drilling techniques are not sufficient. Oil and gas drilling techniques are now being used to go down to the appropriate depth. As a result, water pumping is becoming very energy intense. The deeper the water is, the more energy it takes to bring it up and to irrigate fields. In 2014, California spent an additional $454 in energy to extract ground water to compensate for the drought.
The pumping plant can be damaged by natural wear-and-tear of the propeller, a falling water table, an electrical failure, a malfunction in the filter that removes sand or other debris, and any external that changes the pressure of the overall pumping plant. In the case of pressurized irrigation systems, leaks will change the pressure and the normal operating condition of the pump. Leaks can be caused by a worker, an animal or a machine. Leaks can also be caused by wear and tear. Leaks are very labor intensive to locate (ranchers have to walk every other row in a large field). They usually go undetected until there is physical damage to a crop or to property, or when an increase in utility bills is observed by the farmer, which may be months after the leak started.
Water pumps are used to distribute the water throughout an irrigation system. Anomalous behaviors makes it more difficult to automate the irrigation system by a control system; it also makes the performance of the water pumps less predictable and prevents the effective use of energy management systems. Otherwise energy management systems could be: (1) used to leverage flexibility in the pumps that can be sold to a utility market; or (2) integrated with energy storage systems to use a renewable energy source onsite rather than conventional sources from the grid. See, for example, European patent application publication number EP20120181445 “Methods and apparatus for controlling irrigation systems”, and U.S. patent application Ser. No. 13/844,605 “Digital electrical routing control system for use with electrical storage systems and conventional and alternative energy sources.”
Currently, anomalies are detected by performing a pump efficiency test that measure the water flow, the internal pressure of the pump, and the power drawn by the pump. This defines the operating condition of a pump that can only be of certain values for each type of pump. Pump manufacturers provide pump curves that describe how the pump operates in water flow gallons-per-minute and pressure in feet-of-head for various sizes of pipes. It also provide the overall pump efficiency in percentage and the power drawn in horse-power. Pump tests are labor intensive and are recommended every few years to maintain the pump and reduce the load on power utility grids.
Leaks are a particularly of interest because they waste both water and energy. For water systems beyond the utility company's water meter, such as in farming operations, leaks have been typically identified by the appearance of wet areas on the property, more vigorous vegetation, or by seeing significantly larger utility bills weeks after the leak first begins.
Water is becoming more valuable as it becomes scarcer. Therefore, more farmers are now measuring how much water they consume. They can also optimize crop yield by controlling the amount of water applied to the field at particular time of the year. Current methods of measuring water usage include welding a flow meter into a piping system and taking regular manual readings, or by estimating it from the number of hours the pump was on. Both methods are imprecise and are labor intensive. For instance the operating condition of the pump may change over time, or the flow meter that was installed is not properly installed. Farmers are not always inclined to find a remedy to have more precise measurements, or maintain water records at all as they might be under the scrutiny of regulating bodies to use too much water. More than seventy percent of the world's fresh water supply is used for agriculture.
There is a need for improved methods of detecting anomalies in pumping plants and measure water usage for irrigation.